title: Genes involved in fatty acid metabolism: molecular characterization and hypothalamic mRNA response to energy status and neuropeptide Y treatment in the orange-spotted grouper Epinephelus coioides.
abstract: As in mammals, fatty acid (FA) metabolism plays diverse and vital roles in regulating food intake in fish. Multiple lines of evidence suggest that the effect of FA metabolism on food intake is linked to changes in the level of neuropeptide Y (NPY) in the hypothalamus of the rainbow trout. In mammals, the evidence suggests that FA metabolism regulates feeding via hypothalamic NPY. NPY is therefore considered an important factor that mediates the modulation of food intake by FA metabolism in vertebrates. The stimulatory effect of NPY on food intake is well known. However, to the best of our knowledge, the effect of NPY on FA metabolism in the hypothalamus has not been examined. In this study, we cloned the cDNA of four key enzymes involved in FA metabolism and assessed the effect of energy status and NPY on their mRNA expression in the hypothalamus of grouper. The full-length cDNAs of UCP2 and CPT1a and the partial coding sequence (CDS) of ACC1 and FAS were isolated from the grouper hypothalamus. These genes are expressed in the hypothalamus and during the organogenetic stage of embryogenesis. A feeding rhythm study showed that the hypothalamic expression level of NPY and CPT1a was highly correlated with feeding rhythm. Long-term fasting was found to significantly induce the hypothalamic mRNA expression of NPY, CPT1a and UCP2. An in vitro study demonstrated that NPY strongly stimulated CPT1a and UCP2 mRNA expression in a time- and dose-dependent manner. Collectively, these results suggest that these four genes related to FA metabolism may play a role in regulating food intake in grouper and, that NPY modulates FA metabolism in the grouper hypothalamus. This study showed, for the first time in vertebrates, the effect of NPY on the gene expression of FA metabolism-related enzymes.
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Tang
authors.forename: Caiyun
authors.initials: C
authors.lastname: Sun
authors.forename: Aifen
authors.initials: A
authors.lastname: Yan
authors.forename: Shuge
authors.initials: S
authors.lastname: Wu
authors.forename: Chaobin
authors.initials: C
authors.lastname: Qin
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wensheng
authors.initials: W
authors.lastname: Li
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass / Q000235:genetics* / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D004435:Eating / Q000187:drug effects* / Q000235:genetics; D005215:Fasting; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects* / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000071246:Uncoupling Protein 2
chemical_list: D017931:DNA Primers; D005227:Fatty Acids; D029941:Fish Proteins; D007473:Ion Channels; D024101:Mitochondrial Proteins; D009478:Neuropeptide Y; D012333:RNA, Messenger; D000071246:Uncoupling Protein 2; D002334:Carnitine O-Palmitoyltransferase; D064429:Fatty Acid Synthases; D000103:Acetyl-CoA Carboxylase
keywords: ACC1; AMP-activated protein kinase; AMPK; CPT1a; FAS; Fatty acid metabolism; Food intake; ICV; NPY; Orange-spotted grouper; RT; UCP2; acetyl-CoA carboxylase 1; body weight; bw; carnitine palmitoyltransferase 1a; fatty acid synthase; i.p.; intracerebroventricular; intraperitoneal; neuropeptide Y; reverse transcription; uncoupling protein 2